Description
As an electronic people, it is often required to solder leaded components as well as the SMD components. This kit provides the SMD components soldering basic practices.
This circuit composes of NE555 which constitutes a multi-vibrator, the pulse oscillation signal passes through the NE555 Pin 3 outputs to CD4017 for counting. CD4017 will follow the input pulse. The signal outputs high level to Q0-Q9 in turn, illuminating the corresponding LED, these LEDs are arranged in a circle to form a flowing light. When CD4017 counts to 10, the carry end C0 changes from low to high, drive the transistor Q1-Q4 to turn on, so as to light up the four LEDs at the corner of PCB, after the next pulse, the C0 terminal returns to low level, four LEDs at corner goes out, and the cycle repeated.
